Recent activity

The geomagnetic field was quiet to active on December 9. Solar wind speed
ranged between 444 and 617 km/s (all day average 494 km/s - decreasing 82 km/s
from the previous day).

Solar flux measured at 20h UTC on 2.8 GHz was 92.4. The planetary A
index was 7 (STAR Ap - based on the mean of three hour interval ap
indices: 6.8). Three hour interval K indices: 11100124 (planetary),
12211223 (Boulder).

The background x-ray flux is at the class A4 level.

At midnight there was 1 spotted region on the visible solar disk.
The solar flare activity level was low. A single C class event
was recorded during the day.

Region 10930 still has a weak magnetic delta structure in the southern part
of the single penumbra. The region was mostly quiet, however, there is still a chance of an M class flare.
Flare: C1.3 at 10:59 UTC.

Coronal mass ejections (CMEs)

December 7-9: No obvious partly or fully Earth directed CMEs
were detected in LASCO imagery.

Coronal holes

No obvious coronal holes are currently in or approaching Earth facing
positions.

Processed SOHO/EIT 284 image at 19:06 UTC on November 24. The
darkest areas on the solar disk are likely coronal holes.

Forecast

The geomagnetic field is
expected to be mostly quiet on December 10-12.

Coronal holes (1)

Coronal mass ejections (2)

M and X class flares (3)

1) Effects from a coronal hole could reach Earth
within the next 5 days. When the high speed stream has arrived the
color changes to green.
2) Effects from a CME are likely to be observed at Earth within 96
hours.
3) There is a possibility of either M or X class flares within the next
48 hours.

Propagation

Long distance low and medium
frequency (below 2 MHz) propagation
along east-west paths over high and upper middle latitudes is poor to very poor. Propagation on long distance northeast-southwest paths is
very poor.

Monitoring remarks from a location near N58E06: The most frequently
heard stations from Newfoundland (590, 640, 710, 800 and 930 kHz) had weak
signals, otherwise there were few TA signals around.

Data for all numbered solar regions according to the Solar Region
Summary provided by NOAA/SEC. Comments are my own, as is the
STAR spot count (spots observed at or inside a few hours before
midnight) and data for regions not numbered by SEC or where SEC has
observed no spots.
SEC active region numbers in the table below and in the active region
map above are the historic SEC/USAF numbers.

Active region

Date numbered

SEC
spot
count

STAR
spot
count

Location at midnight

Area

Classification

Comment

10929

2006.12.04

N03E02

plage

10930

2006.12.04

3

10

S04E19

0380

CKO

beta-deltaclassification was DKC at midnight

Total spot count:

3

10

SSN:

13

20

Monthly solar cycle data

Month

Average solar
flux at Earth

International sunspot number

Smoothed sunspot number

2000.04

184.2

125.5

120.8
cycle 23 sunspot max.

2000.07

202.3

170.1

119.8

2001.12

235.1

132.2

114.6 (-0.9)

2005.09

91.1

21.9

25.8 (-1.6)

2005.10

77.0

8.7

25.5 (-0.3)

2005.11

86.3

18.0

24.9 (-0.6)

2005.12

90.7

41.1

23.0 (-1.9)

2006.01

83.4

15.3

20.8 (-2.2)

2006.02

76.5

4.9

18.6 (-2.2)

2006.03

75.4

10.6

17.3 (-1.3)

2006.04

89.0

30.2

17.1 (-0.2)

2006.05

80.9

22.2

17.3 (+0.2)

2006.06

76.5

13.9

(16.3 predicted, -1.0)

2006.07

75.7

12.2

(14.7 predicted, -1.6)

2006.08

79.0

12.9

(14.2 predicted, -0.5)

2006.09

77.8

14.5

(14.1 predicted, -0.1)

2006.10

74.3

10.4

(13.0 predicted, -1.1)

2006.11

86.3

21.5

(11.5 predicted, -1.5)

2006.12

93.8 (1)

12.8 (2)

(11.3 predicted, -0.2)

1) Running average based on the
daily 20:00 UTC observed solar flux
value at 2800 MHz.
2) Unofficial, accumulated value based on the Boulder (NOAA/SEC)
sunspot number. The official international sunspot number is typically
30-50% lower.

This report has been prepared by Jan
Alvestad. It is based partly on my own observations and analysis,
and
partly on data from some of these solar data sources.
All time references are to the UTC day. Comments and suggestions are
always welcome.